Discharge valve mechanism and high-pressure fuel supply pump including the same

Abstract

Provided is a discharge valve mechanism capable of improving responsiveness when a discharge valve is opened, and a high-pressure fuel supply pump including the discharge valve mechanism.

The invention claimed is: 
     
       1. A discharge valve mechanism comprising:
 a valve seat portion which has a primary-side flow path; 
 a valve body which seats on and separates from the valve seat portion; 
 a guide portion which is formed so as to be slidable on an outer surface of the valve body and guides movement of the valve body in a contacting/separating direction with respect to the valve seat portion, 
 wherein the guide portion includes a portion in which a gap from an outer surface of the valve body is set to a predetermined value or less, 
 a first secondary-side flow path which allows an internal space on an upstream side of the guide portion to communicate with an external flow path is formed so as to allow a fluid to flow out to a side in a moving direction of the valve body, and 
 a second secondary-side flow path which allows an internal space on a downstream side of the guide portion to communicate with the external flow path is formed so as to allow a fluid to flow out to the side in the moving direction of the valve body; and 
 a stopper portion which is formed to abut on the outer surface of the valve body and regulates a movement of the valve body in a lift direction, 
 wherein the stopper portion is formed at a position between the guide portion and the second secondary-side flow path. 
 
     
     
       2. The discharge valve mechanism according to  claim 1 , further comprising a tubular valve holder which holds the valve body inside the valve holder and in which the guide portion is formed. 
     
     
       3. The discharge valve mechanism according to  claim 2 ,
 wherein the first secondary-side flow path includes a first through hole which penetrates the valve holder in a radial direction at a position closer to the valve seat portion than the guide portion, and 
 the second secondary-side flow path includes a second through hole which penetrates the valve holder in the radial direction at a position farther from the valve seat portion than the guide portion. 
 
     
     
       4. The discharge valve mechanism according to  claim 3 ,
 wherein an annular flow path is formed radially outside the valve holder, and 
 each of the first through hole and the second through hole opens to the annular flow path. 
 
     
     
       5. The discharge valve mechanism according to  claim 3 ,
 wherein a plurality of the first through holes are formed in a circumferential direction of the valve holder, and 
 all the first through holes have the same hole diameter. 
 
     
     
       6. The discharge valve mechanism according to  claim 3 ,
 wherein a plurality of the second through holes are formed in a circumferential direction of the valve holder, and 
 all the second through holes have the same hole diameter. 
 
     
     
       7. The discharge valve mechanism according to  claim 3 ,
 wherein the first through hole and the second through hole are formed to have the same hole diameter. 
 
     
     
       8. The discharge valve mechanism according to  claim 3 ,
 wherein a hole diameter of the first through hole is set to be equal to or more than a hole diameter of the second through hole. 
 
     
     
       9. A discharge valve mechanism comprising:
 a valve seat portion which has a primary-side flow path; 
 a valve body which seats on and separates from the valve seat portion; 
 a guide portion which is formed so as to be slidable on an outer surface of the valve body and guides movement of the valve body in a contacting/separating direction with respect to the valve seat portion, 
 wherein the guide portion includes a portion in which a gap from an outer surface of the valve body is set to a predetermined value or less, and 
 a first secondary-side flow path that allows a space on an upstream side of the guide portion and an internal space formed at a position of the guide portion to communicate with an external flow path is formed so as to allow a fluid to flow out to a side in a moving direction of the valve body, and 
 a second secondary-side flow path that allows an internal space on a downstream side of the guide portion to communicate with the external flow path is formed so as to allow a fluid to flow out to the side in the moving direction of the valve body; and 
 a stopper portion which is formed to abut on an outer surface of the valve body and regulates movement of the valve body in a lift direction, 
 wherein the stopper portion is formed on a downstream side of the guide portion, and 
 the second secondary-side flow path is formed to allow an internal space formed at a position of the stopper portion to communicate with the external flow path. 
 
     
     
       10. The discharge valve mechanism according to  claim 9 , further comprising a tubular valve holder which holds the valve body inside the valve holder,
 wherein the first secondary-side flow path includes a first through hole which penetrates the valve holder in a radial direction, 
 the second secondary-side flow path includes a second through hole which penetrates the valve holder in the radial direction at a position farther from the valve seat portion side than the first through hole, 
 a plurality of the first through holes and a plurality of the second through holes are formed at intervals in a circumferential direction of the valve holder, and 
 the first through hole and the second through hole are disposed such that circumferential positions of the first through hole and the second through hole do not overlap each other. 
 
     
     
       11. The discharge valve mechanism according to  claim 9 , further comprising a tubular valve holder which holds the valve body inside the valve holder and in which the guide portion is formed,
 wherein the valve holder includes an inner diameter enlarged portion formed such that an inner diameter of a portion from the guide portion side toward the valve seat portion side gradually increases toward the valve seat portion side, and 
 a part of the first secondary-side flow path opens to an inner peripheral surface of the inner diameter enlarged portion of the valve holder. 
 
     
     
       12. A high-pressure fuel supply pump comprising the discharge valve mechanism according to  claim 1 . 
     
     
       13. A high-pressure fuel supply pump comprising the discharge valve mechanism according to  claim 9 .